John w



emanan smrns PATENT carros.

JOHN WV. COCHRAN, OF NEXV YORK, N. Y.

MODE OF CONNECTIN'G THE SECTIONS OF METALLIC TUNNELS.

Specification of Letters Patent No. 191,685, dated March 23, .1858.

T 0 all whom it may concern:

Be it known that I, JOHN W. COCHRAN, residing in the city, county, andState of New York, have invented a newv and useful improvement inmetallic tunnels, to be used for submarine or submerged tunnels, alsofor lining railway-tunnels instead of brick or other arching; and I dodeclare that the following is a full and exact description thereof,reference being had to the accompanying drawings and to the letters ofreference marked thereon.

In constructing my tunnels I employ what I call a series of compoundarches welded or riveted together by any well known process the saidarches being internally braced in such a manner that the externalpressure upon the tunnel shall act both as thrust and tension upon thesaid internal braces from whatever point the external force or pressuremay be greatest.

To construct what I call a compound arch I take a wrought iron plate ofany given dimensions and roll or form it into a trough of semi tubeshape, longitudinally; in this shape I call the plate so formed, a'simple arch, or inverted arch. If this plate thus formed is ofsufficient length, for the purpose I roll or form it in such a manner asto bring the two ends together in the form of a hoop, ring, ellipsis orany other required shape or form and when the two vends are secured byrivets or welding I call' the hoop or ellipse a compound arch, as it isarched both laterally and longitudinally. The edges of the hoop orellipse are flanged or bent in such a manner that they will lit nicelyand firmly into each other so that they may be welded or riveted firmlytogether' water tight. This series of arches may be continued to anyrequired length but if in submerged tunnels the series may beconstructed in sections.

When the arches are being put together they are also braced laterallyand vertically with wrought iron tubes or other material as beforementioned which is more fully shown in the drawings.

I propose to construct my tunnel for submarine purposes upon land or'camels and launch it in any of the well-known ways and Y float thetunnel by its own buoyancy to the locality where it is to be submerged.A channel is there excavated in the bottom of the river in the earth ofsufficient depth to receive the tunnel and to bring it to a suflicientdepth not to obstructnavigation and to protect the tunnel from shipsanchors or other accident. After the channel is sufficiently preparedand the tunnel is floated over the excavated channel water is then letinto the tunnel sufficiently to gradually overcome its buoyancy till itsettles to its proper place in the excavated channel when the tunnel iscovered with sand rock or' other material to overcome its buoyancy afterthe water is pumped out. The ends of the tunnel may have inclinedextensions of suliicient length to bring them to a level with the earthor access and egress may be had by inclined circular ways or otherwiseas may now explain.

At the ends of the sections of the tunnel I attach strong iron armswhich project at an angle over each end of the dierent sections, thesearms project at such an angle that if two ends of the sections areplaced near each other the arms of each section shall cross the other atan angle of say twenty seven degrees. I then pass a wire cable aroundthe tunnel over the points or intersections of the arms and then byconnecting the two ends of the cable by means of a suitable screw jointthis cable acts as a continuous wedge in the inclined arms and as thescrew is turned the two sections of the tunnel are drawn firmlytogether, the flanges being suitably packed with india rubber or othersuitable material to make a water tight joint till it can be welded orriveted after the water is pumped out.

In the accompanying drawings Figure 1 shows a transverse section or endview; Fig. 2 an outside or horizontal view and Fig. 3, shows alongitudinal view of the tunnel as it might appear deposited in the bedof the river the blue lines showing the water above it.

a, a, a, shows the rim or circumference of the tunnel; o road ways ortrack; c, c, c, vertical supports or braces; f, f, and f,

and of course that the greatest eXternal pressure Will be greatest atthe top and bottom of the tunnel. In this case the strain upon theinternal supports will be a thrust or negative strain upon the Verticalsupports and tension or positive strain upon the horizontal braces, andif the outside pressure is greatest horizontally the strain upon theinternal braces will be reversed the thrust being brought upon thehorizontal braces and tension upon the vertical braces.

CZ, d, are elevated Walks at the sides for foot passengers; e, e,aqueducts for carrying fresh Water from shore to shore if required, `orgas pipe may be also used for conveying gas.

z', z', z', are the inclined arms attached to the ends of the sections,through Whose points of intersection the Wire cable is passed fordrawing the tWo sections together as before described; deeper excavationof the channel at this point being required for the arms to drop into.

I prefer the oval or elliptical shape as less depth of excavation isrequired, and it also being a better shape for floating. The tunnel maybe ballasted both before or after it is submerged.

Vhat I claim as my invention and desire to secure by Letters Patent inmetallic tunnels, is-

The inclined arms, z', attached to the ends of the sections and thecable, L, for securing and connecting the same substantially as hereinset forth.

J. lV. COCHRAN.

